Side windows behind seats

The window cutout for windows just behind the seats has two cross members for apparent stiffening. With a window installed, there is is presumably no structural strength decline given the surrounding reinforcement, but the window has to take up the slack of that reinforced metal.

The large area means more exchange of heat/cold/light versus an insulated van wall in the same area. Still, a window-less van without cross-venting is a dreary idea.

Rear side windows

Rear side windows are frequently added in addition to the side windows behind the seats. Some owners want that sleek look of having windows the entire van length and go with full-size windows matching the side windows (some even want the sleek look so much that the windows are non-venting). Others go with 30" X 10" slider windows.

My plan had been to install 30" X 10" slider windows for ventilation, but with a 10-speed Fantastic fan overhead near the foot of the bed, the fan will probably do a lot more ventilating.

The rear is typically the sleeping area. Installing rear side windows and/or side windows creates a privacy issue at night with the interior illuminated, or even when parked in the daytime (security issue for gear inside).

Also, note that the two reinforcing panels have to be cut through to install windows; how this affects vibration and noise is unclear. In my mind, I am comparing windows with poor insulating value to a fully insulated side area, possibly with a nook for storage or hanging of items (eyeglasses, flashlight, clothes, etc).

With more thinking, I am trending away from rear side windows. The rear of the van is a key area for gear and sleeping, so I see little benefit to adding light (plus I plan to add high-grade lighting), and the overhead fan will be more effective to introduce or remove hot or cold air than windows.

Rear door windows

Rear door windows are debatable: I find the mirrors entirely adequate when driving.

Rear windows make the entire van a fishbowl when driving towards a bright area and/or when the van is illuminated at night. They increase the security hazard of seeing into the van by yet one more window with more light inside when parked and away. Thus one probably has to pull down shades when leaving the van parked, both for heat/cold and prying eyes.

The “fishbowl” point was driven home to me when I happened to see two new Sprinters replete with all windows one evening when cycling—no privacy at all; I could see inside the van and the driver from the rear. I’m not keen on that idea, particularly when parked.

Another factor is the large surface area that increases heat transfer (cold or heat) as well as less noise reduction, that is, compared to insulating the rear doors in their entirety for heat/cold/sound. My inclination is to skip the rear windows.